Apple has warmed up for the top-secret launch planned for 12 September by revamping its consumer-oriented iMac and Mac Mini models.

The company is expected to announce new iPods next week, but in the meantime, the iMac range has been completely revamped. Four new models have been released, all using Intel’s latest Core 2 Duo processor, replacing three earlier Core Duo models.

Prices start at just £679 for a 1.83GHz model with 17in flat-panel screen, 512MB of Ram and a 160GB hard disk. There’s also a 2GHz version with 1GB of Ram and 17in screen for £799, and a 2.16GHz model that has a 20in screen for £999.

And, for the first time, Apple is bringing out a 24in version of the iMac, priced at £1,349.

The addition of the low-cost £679 model, gives Apple its cheapest ever price point for the iMac range, confirming the company’s intention to compete more aggressively with computer manufacturers now that it is using the same Intel processors as the rest of the PC industry.

And, at the lowest end of the Mac range, the diminutive Mac Mini also received a bit of a revamp – albeit a more modest one.

The £399 model has been upgraded from a Core Solo processor running at 1.66GHz to a Core Duo running at the same speed. The £529 version that previously had a 1.66GHz Core Duo has received a minor speed bump to 1.83GHz. The Mac Mini is sold without accessories such a keyboard, mouse or monitor.

These upgrades should help Apple continue the strong sales it has enjoyed since it began using Intel processors in January.

However, the real excitement is likely to take place next week when Apple is expected to announce new iPods and its long-awaited video-on-demand service for downloading Hollywood films. The iPods are expected to have widescreen displays, making it easier to watch video.